Apparatus for cutting a web of material

ABSTRACT

This invention relates to an improvement in an apparatus for cutting a web of material, the apparatus including supply means for the web of material, a first feeding means for feeding the web to a cutting means, a cutting means, and a second feeding means behind the cutting means, and the improvement comprising movable guide means for the web positioned between the cutting means and the second feeding means, said first feeding means being stationary and said second feeding means being in operation during a cutting operation.

United States Patent Witte [54] APPARATUS FOR CUTTING A WEB OF MATERIAL[72] Inventor: Horst Wltte, Wiesbaden-Biebrich, Germany [22] Filed: Oct.22, 1970 21 App]. No.: 83,005

[30] Foreign Application Priority Data Sept. 10, 1970 Germany ..P 20 44820.8

[52] US. Cl ..83/l56, 83/175, 83/424 [51] Int. Cl ..B26d 7/14 [58] FieldofSearch ..83/l10, 156,175,424

[56] References Cited UNITED STATES PATENTS 3,468,202 9/1969 Hollis..83/l75 [451 May 30, 1972 3,542,267 11/1970 Ida ..83/l75X 3,587,3766/1971 Hirano ..83/175X Primary Examiner-Andrew R. J uhasz AssistantExaminer-David R. Melton Attorney-James E. Bryan 57 ABSTRACT Thisinvention relates to an improvement in an apparatus for cutting a web ofmaterial, the apparatus including supply means for the web of material,a first feeding means for feeding the web to a cutting means, a cuttingmeans, and a second feeding means behind the cutting means, and theimprovement comprising movable guide means for the web positionedbetween the cutting means and the second feeding means, said firstfeeding means being stationary and said second feeding means being inoperation during a cutting operation.

4 Claims, 4 Drawing Figures Patented May 30, 1972 3,665,796

2 Sheets-Sheet 1 mv ENTOR HORST WITTE ATTOR N EY Patented May 30 1972 2Sheets-Sheet 2 mvmwon HORST WIT TE ATTORNEY material, at least onefeeding device for the web of material ahead of the cutting station, acutting station, and a feeding device behind the cutting station.

The apparatus according to the invention may be used either as anindependent apparatus or as a component of a copying apparatus.Irrespective of which particular copying process is employed, it is ofadvantage to use the copying material in a copying apparatus in the formof an endless web stored upon a magazine roll, from which a lengthdetermined by the size of the original to be copied is withdrawn andsevered. Therefore, the apparatus according to the invention may be usedin thermographic and electrophotographic apparatuses, and also inphotoprinting machines. Copying machines in which several rolls ofcopying material are stored are of particular advantage, because, inthis case, copying material may be selectively withdrawn from one of therolls, depending upon the width of the original, and then severed. Theapparatus according to the invention is particularly suitable for use insuch machines.

Normally, the web of material should be fixed and tensioned during thecutting operation, in order to achieve a clean cut. From publishedGerman Pat. application No. 1,461,239 (DOS), for example, a device forcutting a web of material is known in which the web of material is heldunder tension between a clamp and a tightening-up roller at the time ofcutting. v

In the case of automatic copying machines, such as photoprintingmachines, this would mean that the feeding devices ahead of and behindthe cutting station are stopped for the cutting operation. However,since it is of advantage to feed the copying material and the originalat the same constant speed, so that they reach the exposure stationsimultaneously, in an overlying position, and pass it at the steadyspeed required for correct exposure, it would be more advantageous forthe feeding device behind the cutting station to operate at a constantspeed even during the cutting operation. On the other hand, it isnormally necessary to switch off the feeding device ahead of the cuttingstation when a sufficient length of copying material, corresponding tothe scanned length of the original, has been 'withdrawn from themagazine roll, to enable the cutting operation to be performedaccurately and with as little trouble as possible. This means thatduring the cutting operation, the web of copying material would bebetween a stationary and an operating feeding device. As a consequence,higher tensions would be created in the web which would cause it tobreak.

Several attempts have been made to solve this problem. German utilityPat. No. 1,977,676, for example, describes a cutting device in which thefeed speed behind the cutting station is lower than the feed speed aheadof the cutting station. ln this manner, a loop is formed in the web ofmaterial behind the cutting device when the web is withdrawn from themagazine roll. This loop enables the web of material to be severedbetween a stationary and an operating feeding device without creatingtensions in it. However, this device is unsuitable for very longoriginals, because the loop would have to be correspondingly large andcould be passed on only with difficulty. Therefore, an additionalscanning device must be provided for this case, which responds to aparticular size of the loop and initiates a re-adjustment of the feedspeeds or temporarily disconnects the feeding device ahead of thecutting station. This device has the advantage that, due to theformation of a loop, no tensions occur in the web of material which maycause it to break, but, on the other hand, the feeding device must betemporarily arrested when long originals are to be copied. Moreover, theweb of material is not so tight as is desirable for a clean and smoothcut.

The present invention provides a cutting apparatus which avoids theabove-described drawbacks. The apparatus should be such that it cuts atightened web of material, the front portion of which is continuouslyconveyed, whereas the trailing portion thereofis maintained stationarybefore and during the cutting operation, without breaking the web ofmaterial.

As a further embodiment of the invention, the cutting apparatus shouldbe suitable for use in copying machines in which a web of material isselectively withdrawn from one of several magazine rolls.

The present invention deals with an apparatus for cutting a web ofmaterial which comprises at least one magazine roll for the web ofmaterial, at least one feeding device for the web of material ahead ofthe cutting station, a cutting station, and a feeding device behind thecutting station. In the apparatus, a movable guide means for the web ofmaterial ispositioned between the cutting station and the feeding devicebehind the cutting station and, during the cutting operation, thefeeding device ahead of the cutting station is stationary, whereas thefeeding device behind the cutting station is in operation;

The apparatus according to the invention is particularly suitable forcutting a web of paper. The web-like material is reeled upon a magazineroll from which it is withdrawn when desired and fed to the cuttingdevice by means of a feeding device.

Several magazine rolls may be provided on which webs of material ofdifferent properties, for example, of different widths, may be stored.The material is selectively withdrawn from one of these rolls andconveyed to the cutting station by means of the feeding device connectedwith it.

After passing the cutting station, the web of material is conducted, bymeans of guide means, to a feeding device which transports it evenduring the cutting operation. The severed sheets may be subjected to afurther treatment, for example, when the apparatus is a component of acopying machine.

The feeding devices may consist, in known manner, of endless conveyorbelts, of pairs of rollers, or the like. The movable guide means behindthe cutting station has the function of yielding when the web ofmaterial presses upon it and thus opening a shorter path for the web ofmaterial between the cutting station and the feeding device behind thecutting station. The guide means causes the web of material to betightened during the cutting operation. On the other hand, it preventsthe web of material from being tightened by a. jerk and break, when thefeeding device ahead of the cutting station is stopped shortly beforethe cut, whereas the feeding device behind the cutting station continuesits operation.

If the apparatus according to the'invention forms part of aphotoprinting machine, for example, in which a web of material isselectively drawn from one of several magazine rolls,

of the web of material is slightly pulled back from the cutting 7station after the cutting operation, because trouble may occur if theleading edge of this web of material is still at the cutting stationwhenanother web of material is brought up. This is avoided by providing theguide means for the individual webs of material ahead of the cuttingstation with return springs. The portion of the web which, immediatelybefore cutting, is situated between the stationary feeding device aheadof the cutting station and the operating feeding device behind thecutting station pushes the movable guide means up. By the weight of themovable guide means, the web of material is tightened and deforms thereturn springs. After the cutting operation, the web of material iswithout tension, the movable guide means is lowered, the return springsare lifted, and thereby pull the leading edge of the web of'materialslightly back from the cutting station.

The cutting station preferably comprises a stationary lower blade and amovable upper blade clamped in a support. The cutting edge of the upperblade is roof-shaped when seen in the direction of feed of the material.Thus, it cuts the material from the outside to the inside.

In order to achieve a clean cut, the upper blade and the lower blademust be pressed upon each other within the cutting zone. Normally, theupper blade is several mm thick and is pressed against the lower bladeby means of springs, for example. This arrangement is expensive, becauseit requires 'an accurate mounting and because damaged upper blades canbe replaced only with difficulty. Consequently, a very thin upper bladeof an elastic material in web form is used according to the invention.Preferably, it consists of a spring steel band of less than l mmthickness. Because of its easier production, the upper blade maycomprise two individual halfblades the cutting edges of which arelikewise arranged in a roof-like position to each other when seen in thedirection of transport of the material.

The upper blade or blades are provided with a break over their entirelength and thus are pressed over their entire length against the lowerblade under tension. Whereas above the break the upper blade or upperblades form an angle of 90 or less with the lower blade, the angle belowthe break is slightly larger than 90. By this arrangement, a uniformpressure of the blades upon each other is achieved during the entirecutting operation.

In the'following, the invention will be described in detail withreference to one embodiment thereof in which the apparatus forms part ofa photoprinting machine, taken in connection with the accompanyingdrawings,

In the drawings; I

FIG. 1 is a vertical section through the apparatus according to theinvention, seen in the direction of the feed of the material,

FIG. 2 is a perspective view of the movable guide means,

FIG. 3 is a front elevation of the cutting station, without drive andlateral guide means, and

' FIG. 4 is an enlarged view of a cross-section along line A-B throughthe cutting station of FIG. 3.

The photoprinting paper is stored on two magazine rolls .1 and 2, theaxle ends 3 of which are held in the mountings 4. The paper webs 5 and 6are withdrawn from the magazine rolls 1 and 2 by means of two pairs ofdraw-off rollers 7 and 8 and conveyed by means of two pairs of feedrollers 9 and 10 through the guide plates 11 and 12 to the cuttingstation 13. Behind the cutting station 13, the web of paper selected,viz. either 5 or 6, is transported past a guide bar 14 and the movableguide means 15 to the pair of rollers 16. This pair of rollers 16transports the web 5 or the web 6 between the guide plates 17 to thepair of inlet rollers 18 of the exposure station (not shown), theleading edge of the paper web 5 or the web 6 and the leading edge of theoriginal 19 arriving in an overlying position at the inlet rollers 18.

Displaceable rollers 20 and 21, respectively, are positioned between thepair of draw-off rollers 7 and the pair of feed rollers 9, in one case,and the pair of draw-off rollers 8 and the pair of feed rollers 10, inthe other case. The displaceable rollers 20 and 21 can be shifted intheir guides 22 and 23, respectively, to assume positions 20' and 21',respectively, so that a sufficient quantity of paper freed from theweight of the rollers is always available at the feed rollers 9 or 10.The guide plates 11 and 12 are provided with return springs 24 and 25,which cause the leading edge of the paper web 5 or 6 to be pulled backafter the cutting operation.

The cutting station 13 consists of a stationary support for the lowerblade 26, which carries the lower blade 27, and a movable support forthe upper blade 28, which carries the upper blade 29.

The support 28 for the upper blade 29 is provided with guide bars 30which are guided in guide rolls 31. The guide rolls 31 are attached tothe side walls (not shown) of the housing. The guide bars 30 and thesupport 28 for the upper blade 29 connected with them are driven by aneccentric shaft 32. FIG. 3 shows the blades 27 and 29in the openedposition. The upper blade 29 contains a break along the line 33. Theupper blade 29 consists of two blades 29 a and 29 b the cutting edges ofwhich form a roof-like arrangement when seen in the direction of feed ofthe paper. Even in the open position of the cutting station 13, the twoouter ends of the blades 29a and 29b of the upper blade are pressedagainst the lower blade 27 with tension. In FIG. 4, the shape of theupper blade portion 29a is distinctly visible.

The movable guide means 15 consists of a curved guide plate 34 to whichthe rods 35, 36a and 36b with the guide rolls 37 are attached. The webof paper is' conveyed along the curved guide plate 34. The guide plate34 is movably mounted by the guide rollers 37 which slide in the guiderails 38, 39a and 38b. The rods 36a and 36b and the guide rails 39a and39b connectedwith them are in a mirror-image relation to each other (seeFIG. 2). The rod 35 and the. guide rail 38 are swiveied through withrespect to the rods 36a and 36b and the guide rails 39a and 39bconnected therewith (see FIG. 2).- By this arrangement, a lateralcapsizing of the movable guide means 15 is avoided. The guide rails 38,39a, and 39b are fastened to a fixedly mounted angle iron 40.

Beneath the hinged guide plate 41, a collecting trough 42 for wastepaper is provided which is accessible from both ends of the apparatus.

An original 19 is fed into the apparatus from a location on the feedtable 43 which is determined by its width, and is conveyed to theexposure station by means of the pairs of feed rollers 44, 45, and 18.On its path, the original is conducted past scanners 46. Depending onwhich of the scanners 46 is contacted by the original 19, one of the twomagazine rolls 1 or 2 is selected. The operation will be described inthe following with reference to a case in which the magazine roll 1 isselected.

When the leading edge of the original 19 actuates the scanners 46, thepair offeed rollers 9 begins to rotate and feeds the web of paper 5 at aspeed which corresponds to the feed speed of the original 19 through theopened cutting station 13 and between the movable guide means 15 and theguide plate 41 to the pair of rollers 16. This latter pair of rollersseize the leading edge of the paper web 5 and convey it further. At thepair of inlet rollers 18 of the exposure station, the paper web 5 meetswith the original 19 in such a manner that the leading edges of bothmaterials take an overlying position. From here, the materials areconveyed together to the exposure station.

Due to the rotation of the pair of feed rollers 9, thedisplaceableroller 20 is lifted in its guide rails until it maximallyassumes position 20'. Thereby, it pushes the switch 47 into position47', which causes the pair of draw-off rollers 7 to begin rotation. Thispair of draw-off rollers 7 withdraw the web of paper 5 from the magazineroll 1 at a speed which exceeds that of the pair of feed rollers 9.Therefore, the displaceable roller 20 is lowered again and disconnectsthe pair of feed rollers 7. This procedure may be repeated severaltimes, depending upon the length of the original used. A friction brake(not shown) positioned between the axle end 3 and the roll core 48, andthe weight of the displaceable roller 20 prevent the formation of a loopin the paper web 5 when the pair of draw-off rollers 7 has been switchedoff.

When the trailing edge of the original 19 passes the scanners 46, thepair of feed rollers 9 are switched off. A brake (not shown) providedwithin the pair o f feed rollers 9 prevents the rollers from rolling onfor an appreciable time after being switched off. After an adjustabledelay which depends upon the copying speed the paper is cut. During thisdelay, the pair of rollers 16 lying behind the cutting station 13continue their conveying operation. Thereby, the web of paper 5 istightened and is pressed upon the movable guide means 15, thus causingit to be displaced within its guide rails 38, 39a, and 39b in thedirection of thearrow shown in FIG. 1. By the tightening of the paperweb 5, the return springs 24 are deformed. By the guide bar 14, the webof paper 5 is maintained in a horizontal position in the neighborhood ofthe blades and near the lower blade 27. After the delay, the cuttingoperation is performed by a single revolution of the eccentric shaft 32.The guide bars 30 and the support 28 for the upper blade 29 firmlyattached to them execute a lowering and lifting movement.

After the cutting operation, the movable guide means 15 returns to itsoriginal position. The return springs 24 are lifted and thus pull theleading edge of the paper web 5 slightly back from the cutting station13. The cutting station 13 is thus made free, so that, in the followingoperation, paper web 6 may be conveyed to it without causing trouble.

It will be obvious to those skilled in the art that many modificationsmay be made within the scope of the present invention without departingfrom the spirit thereof, and the invention includes all suchmodifications.

What is claimed is:

1. In an apparatus for cutting a web of material including supply meansfor at least one web of material, at least one first feeding means forfeeding the web to a cutting means, a cutting means, and a secondfeeding means behind the cutting means, the improvement which comprisesmovable guide means for the web positioned between the cutting means andthe second feeding means, said first feeding means being stationary andsaid second feeding means being in operation during a cutting operation.

2. An apparatus according to claim 1 including guide plate means aheadof the cutting means and being provided with return spring means,whereby the leading edge of the web of material can be retracted fromthe cutting means after the cutting operation.

3. An apparatus according to claim 1 in which the cutting meanscomprises a stationary lower blade, a movable upper blade having aroof-shaped cutting edge, and a support for the upper blade.

4. An apparatus according to claim 3 in which the upper blade is made intwo parts from a resilient material and presses against the lower bladeover its entire length by virtue of a break or corrugation in the upperblade.

1. In an apparatus for cutting a web of material including supply meansfor at least one web of material, at least one first feeding means forfeeding the web to a cutting means, a cutting means, and a secondfeeding means behind the cutting means, the improvement which comprisesmovable guide means for the web positioned between the cutting means andthe second feeding means, said first feeding means being stationary andsaid second feeding means being in operation during a cutting operation.2. An apparatus according to claim 1 including guide plate means aheadof the cutting means and being provided with return spring means,whereby the leading edge of the web of material can be retracted fromthe cutting means after the cutting operation.
 3. An apparatus accordingto claim 1 in which the cutting means comprises a stationary lowerblade, a movable upper blade having a roof-shaped cutting edge, and asupport for the upper blade.
 4. An apparatus according to claim 3 inwhich the upper blade is made in two parts from a resilient material andpresses against the lower blade over its entire length by virtue of abreak or corrugation in the upper blade.